Perhaps @burn doesnt phrase it well, however it's not the best idea to instal RPU on top of restoration project 2.3.3 .
RPU is a standalone restoration project pack, and does not require killap's 2.3.3 underneath it.
Installing RP2.3.3 and later on the latest RPU on top of it can cause problems mainly due to ammo files and applied ammo mod.
You see RP2.3.3 uses YAAM and RPU uses vanilla (at least i think so). mix matching ammo files and sfall damage mod settings, may cause glitches like this. Especially if using vanilla ammo files, and YAAM in ddraw.ini as damage formula. those -20DR from .223FMJ turn into -20DT which oddly, adds advanced power armor level damage thershold even to unarmored peasants. So zero damage hunting rifle aginst bandits is not result of some bug but it's the result of your fuckup.
Thanks so much!
OK I have done a clean install and have found the real culprit is the mod CUSTOM PERKS (not saying you are wrong, you also helped me clean up some mess but this bug is spèecifically cause because of a script file in Custom Perks mod)
I have made a new install with only RPU and it works.
Is it safe to install Weapons Redone by Magnus as well? He makes a lot of changes to Throwing, and energy weapons that I like.